A 41-year-old male presented to our hospital with complaints of muscle pain and stiffness in proximal muscles of 2 years with elevated creatinphosphokinase (CK). He had been previously studied in a rheumatology unit of another hospital, but a diagnosis was not achieved. He denies muscle weakness or coluria. There was no family history of myopathy. The muscle complaints were worse in the morning. They improved with non-steroidal anti-inflammatory drugs. He also referred fatigue, and excessive daily sleepiness. He scored 16 in the Epworth Sleepiness Scale (ESS) (normal up to 9).1 He snored, usually drank a glass of red wine each day, and did not take medication.

At examination, he had a body mass index (BMI) of 32. There was normal bulk and tone, and his strength was normal. The sensory examination and reflexes were also normal.

His lab test showed a CK of 353 (normal values …